Proteinaceous Protease Inhibitors: Structural Features and Multiple Functional Faces

Protease inhibitors (PIs) are present in a wide variety of living organisms including microorganisms, plants, and animals. These molecules act as regulators of endogenous proteolytic activity, as participants in many developmental processes and as host's defense components. Because of their important role in living organisms, PIs have been extensively studied in order to allow a better understanding of their structural and functional properties. Intensive works have reported that proteinaceous PIs are potential compounds in several distinct economical and clinical fields. This review aims to describe proteinaceous PIs structure and design, focusing on their multiple potential applications in agriculture; immune system; parasitic, bacterial, fungal, and viral infection; hemostasis; and cancer.